Onthophagus dicranius, Bates, 1887

Delgado, Leonardo & Mora-Aguilar, Eder F., 2019, A new Mexican species of Onthophagus Latreille (Coleoptera: Scarabaeidae: Scarabaeinae), with a revised key to the species of the O. dicranius species complex, Zootaxa 4695 (6), pp. 586-592 : 591

Key to separate species in the Onthophagus dicranius species complex

(partially modified from Howden & Gill 1993 and Kohlmann & Solís 2001)

1. Elytral intervals with stout setae, in three or more rows on second interval; Panama... O. dorsipilulus Howden & Gill, 1987

- Elytral intervals glabrous or with fine setae, in two rows on second interval....................................... 2

2 Punctures of the pronotal disc simple or weakly annulate, small, shallow, and sparse (most separated by two or more puncture diameters)........................................................................................... 3

- Punctures of the pronotal disc with annulate and/or large, deep, and dense (most separated by less than one puncture diameter)............................................................................................... 4

3 Males with frons and vertex flat, with distinct, moderate-sized punctures ( Figs. 9–10 ); females with pronotum evenly convex ( Fig. 10 ); Mexico............................................................... O. subcancer Howden, 1973

- Males with frons and vertex convex, with fine punctures ( Figs. 5–6 ); females with pronotal disc slightly concave ( Fig. 6 ); Mexico................................................. O. chimalapensis Delgado & Mora-Aguilar , new species

4 Pronotum and elytra distinctly setose with short or long setae.................................................. 5

- Pronotum and elytra glabrous or with minute setae.......................................................... 7

5 Elytral intervals with simple punctures; Mexico............................. O. asperodorsatus Howden & Gill, 1993

- Elytral intervals with annulate punctures................................................................... 6

6 Male with a short, broad, distinctly emarginate pronotal protrusion; Costa Rica. O. cryptodicranius Kohlmann & Solís, 2001

- Male with a moderately long, slender, slightly emarginate pronotal horn; female unknown; Costa Rica........................................................................................... nubilus Kohlmann & Solís, 2001

7 Profemora with central region yellow, the rest brown; Costa Rica, Panama..................... O. dicranius Bates, 1887

- Profemora entirely brown.............................................................................. 8

8 Elytra short, moderately rounded; brachypterous; Costa Rica.................. O. inediapterus Kohlmann & Solís, 2001

- Elytra and wings well developed......................................................................... 9

9 Pygidium with deep and simple punctures, apex shiny; male with two laterally compressed and triangular pronotal projections; Belize, Mexico........................................................... O. petenensis Howden & Gill, 1993

- Pygidium with shallow, annulate punctures, surface completely dull; males with a slender, long pronotal horn........... 10

10 Male with a slender, feebly emarginate clypeal horn; female with a weak, frontoclypeal carina; Costa Rica....................................................................................... O. quetzalis Howden & Gill, 1993

- Male with a distally widened, bifurcate clypeal horn; female with a distinct frontoclypeal carina; Panama.............................................................................................. O. kohlmanni Génier, 2017

Figures

FIGURES 9–18. Onthophagus species. 9, ¾ profile view, male of O. subcancer; 10, ¾ profile view, female of O. subcancer; 11, lateral view of genitalia, male of O. subcancer; 12, dorsal view of genitalia, male of O. subcancer; 13, protibia of O. chimalapensis, holotype; 14, protibia of O. aperodorsatus, male paratype; 15, protibia of O. neomirabilis, male; 16, protibia of O. chimalapensis, female paratype; 17, protibia of O. asperodorsatus, female; 18, protibia of O. neomirabilis, female.

FIGURES 1–8. Onthophagus chimalapensis. 1, Habitus, holotype; 2, habitus, female paratype; 3, lateral view of male paratype; 4, lateral view of female paratype; 5, ¾ profile view of male holotype; 6, ¾ profile view of female paratype; 7, lateral view of genitalia, male paratype; 8, dorsal view of genitalia, male paratype.